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angry tapir writes "Using infrared sensors like the ones on television remote controls, Texas A&M University students presented an inexpensive multitouch system at the Computer Human Interaction (CHI) conference in Vancouver. 'I like to consider it an optical force field; it's like a picture frame where we shoot thousands of light beams across and we can detect anything that intersects that frame,' said Jonathan Moeller, a research assistant in the Interface Ecology Lab at Texas A&M University. The frame is lined with 256 IR sensors, which are connected to a computer. When ZeroTouch is mounted over a traditional computer screen it turns the display into a multitouch surface. Taken one step further, if the screen is suspended then a user could paint a virtual canvas."

It only had about a 256 touch-point resolution (16x16), but IR sensors werestandard on most Plato terminals back at the U. of Ill. It had a few terminals scattered off campus, as far away as Hawaii, so would have qualified as one of the first nationwide 'network' systems.

The thing is, there were pretty good attempts at similar things in the late 80s, early 90s. In fact there was a digital desktop (as in a real desk) where you could project things like a calculator and it attempted to find where your finger was using a camera. But computer technology wasn't mature enough to provide the processing power required to do it well. Not to mention projector technology wasn't that great either back then. Keep in mind that the current microcontrollers often outperform the best comput

The term hypocrisy refers to when a person says something or recommends a practice that is contrary to what they actually do. None of what I've said here qualifies under that term.

For what its worth, it still seems to me that they are doing something fairly innovative here... even if it is with old tech. From what I understand, the older stuff that utilized this technology used horizontal and vertical beams only, and had an effective resolution that scaled linearly only with the number of sensors used

I swear we used to have these at work, 10-15 years ago. They were not multi-touch, but that was likely due to the computer interface (serial) and the perhaps more primitive technology at the time. But I'm pretty sure the sensors were infra-red. As I recall, it wasn't necessarily the most accurate system. So, these guys just improved it a bit, or is this truly "revolutionary"?

The technique debuted commercially in the 80s. From Wikipedia:
"The HP-150 from 1983 was one of the world's earliest commercial touchscreen computers. Similar to the PLATO IV system, the touch technology used employed infrared transmitters and receivers mounted around the bezel of its 9" Sony Cathode Ray Tube (CRT), which detected the position of any non-transparent object on the screen."

Plenty of touch overlays for larger screens used this technology, I have a stack of overlays for 32" panels that use IR like this.
A much better options would be something like Next Window Overlays
http://www.nextwindow.com/ [nextwindow.com]
They use a pair of 1 dimesional ir cameras and a bar of ir lights to triangulate objects in their field of view so by placing the cameras in the top two corners of the screen and the ir leds between them you can have a simple bar rather than a square frame like this thing. Mount a bunc

Yes this isn't new technology (other than the multi-touch support). IR touch screens have been around at least since the 80's. You could get add-on bezels for the Apple ][. They are used today for industrial settings where the environment is to harsh or dirty for resistive or capacitive sensors.

At least since the 80's. These were used in a local business museum (Enterprise Square USA) game called Venture. This is really old tech, the only thing remotely interesting is it's ability to now do multi-touch. What next, Pong in 3D!!

Yes it was done before, but without the multi-touch. We had them as well. A bunch of IR-LEDs and IR receivers along the frame of the CRT. Welcome to the 1990's. I'd vote for simply 'improved', certainly it is not revolutionary.

These are commercially available for schools already. Whiteboard manufacturers are buying this off the shelf to integrate with their existing whiteboard systems; they use IR emitters/sensors and hooks up via USB as a standard USB HID multitouch device.

Yep, the only thing that's "new" is how cheaply they can be made today. Back in the 90s I worked with a 10ft by 40ft optical sensor array, which drove a synthesizer as a big performance-art techno theremin.

It had multitouch, though certain combinations would not fire due to line of sight limitations. It was certainly good enough to amaze our druggy audience:)

The latest generation of Sony Readers use infrared touchscreens. This method isn't exactly novel, but here it's applied to a much larger screen and is said to be an add-in component, which is still rather cool. Pick your favorite display and you know you can make it multitouch on top of that.

Try 39 years ago, at least. University of Illinois PLATO IV terminals connected to a Control Data mainframe. We used to do our physics and chemistry homework on these things, and I can tell you from personal experience that they worked great.

Posted this comment earlier, but it got deleted somehow, not sure why.

Disclaimer: I'm the guy in the video.

The biggest difference between our approach and prior infrared touchscreen technologies is the use of one-to-many emitter-sensor pairings. Each infrared emitter is detected by all sensors in view, as opposed to using a single sensor for each emitter. Using a single sensor for each emitter limits the touch detection to two perpendicular grids of parallel light beams. Our approach enables us to reliably

Thanks for the reply. I had worked on a system in the early to mid 90's where we used an IR touch grid to implement "buttons" that were drawn on the screen. I think we used the CarrollTouch system mentioned above.
Guess I should have RTFA. This definitely sounds more interesting than what we did.

> I swear we used to have these at work, 10-15 years ago. They were not multi-touch, but that was likely due to the computer interface (serial) and the perhaps more primitive technology at the time. But I'm pretty sure the sensors were infra-red. As I recall, it wasn't necessarily the most accurate system. So, these guys just improved it a bit, or is this truly "revolutionary"?

They have advanced significantly since then, including multitouch and even interactive objects (think 3D icon-pucks you can place

Err -- my bad, the home-brew ones are not "optical force field" based, as described in the article (similar to original touchscreen technology), they are based on changing with the surface index of refraction when you touch the screen. I suspect the index-of-refraction approach is sensitive to fingerprints, which would be an advantage of capacitive touch or this optical force field.

The "air-canvas" concept is interesting too, and could not be done with either capacitive touch or index-of-refraction.

Don't let them bum you out; the slash in slashdot is more about cutting than sharpness...It sounds like you did something pretty decent, and good luck with your studies. Stick to the low level/hardware interfacing side of the industry. Its a rich area with an increasing lack of expertise.

I mean, if we're going to just go making up shit like "force field" when characterizing a simple grid of eye-beam sensors...

(Hint: where does the "force" come in?)

And yes, the earliest touch-screen technologies were essentially exactly this sort of light-beam interruptor laid near the surface of a CRT. They were soon replaced by surface-acoustical-wave systems and even capacitive feedback through the cathode beam itself.

Well he does have a fair point. This is one of the basic things most electronics students will eventually build in college as a simple exercise and they then drop it due to the lack of real world applications. I've seen people who haven't studied any electronics build similar things and make 3D scanners out of them. It's not like it's particularly hard either. It's harder to drive a small LCD display than to build one of these...

I'd call it a 'field disruption' interface rather than a 'force field' interface.

They're introducing disruptions in a saturated 2D IR field, which allows for multi-touch as well as point density identification. 'Force field'? Not seeing where the standard 'F' (force) we all know from physics, intersects here unless you define the density of disruption as 'force' (F).

Reminds me of the U-Force [wikipedia.org] I got for the original NES - that was over 20 years ago! Still have it in its original box, actually. Maybe in another 25 years it'll be worth something... it certainly wasn't when it came out! It sorta worked for Punch-Out, and not at all for anything else.

I can't remember if the U-Force was what would now be called "multi-touch"... probably not. Didn't RTFA, but at any rate I assume (and would hope) the one in the article works a lot better!

In my local mall, during last christmas holiday, Disney set up an interactive display game to promote their wild-4-disney passes.It consisted of multiple flat-screen tvs setup in a wall with an IR sensor setup in a field-sweep above the whole display. The point was to "drag" christmas ornaments to decorate the tree.

A Brief History of Pads, Part 2: Touch me! [x7.fi]: "PLATO was a series of educational computer terminals that originated from the University of Illinois. In the 1960’s and 1970’s, PLATO contained many features that we take for granted today like e-mail, message boards and online tests. The fourth generation PLATO IV terminal featured a flat (and bright orange) plasma screen that students could touch to answer questions. The touch function was achieved by a series of infrared lights and receptors around

Seen this a long time ago, at least 10 years ago. It was essentially a frame lined with IR sensors facing each other and tracking your hand movements and turned any flat panel display (such as a plasma TV) into a touchscreen surface. While it didn't do multi-touch, it was essentially the exact same concept

The big difference between what we're doing, and what's been done before, is that we are using one-to-many communication between emitters and sensors, as opposed to earlier systems, which use matched emitter/sensor pairs on opposite sides of the display to generate a series of parallel lines in both the x and y directions that can be interrupted.

By reading from a large number of sensors for each infrared emitter, we generate a dense mesh of infrared light beams, which is what enables the sensor to detect multiple touches. Prior infrared systems using parallel beams suffer from ghost touch ambiguities when multiple fingers are on the display. Ours does not. This is the big differentiator between what's been done before and what we've done.

Most SMART boards and other commercial multi-touch sensors, use two cameras in the corners of a screen (some use four), and computer vision algorithms to identify and track touches on the display. Our approach is different in that it generates a more complete visual hull of the interactive area than with these types of systems. Using two cameras means you can only reliably track two touches due to occlusion issues, whereas we can detect 20+ touchpoints with high reliability.

One question.... what are the production costs of the electronics if I wanted to build one of these? (I never quite know what people mean when they say "low cost";) Also, are you planning to publish the schematics?

A lot of people seem to have missed the point here. Either that or the old sensors were cleverer than I thought. Anyhow, I like this approach, I wonder how well it copes with fingers bunched together looking like a single fat finger or whether it can still be confident that the finger it tracks out of a bunch is the same one it tracked going in without getting confused.

As a semi-professional cynic and the guy who tore into the Rice University students [slashdot.org] who's PR dept. claimed they had invented a revolutionary solution to a huge health problem, I had initially thought, as many here have claimed, that this IR-beam touch-screen frame was nothing new. However, I was also trained at one of the the EloGraphics plants (I can't remember where the heck it was now) on how to install and repair those old IR-beam touch screens. I also serviced several other makes of IR-beam touch scree

I bought a HP monitor about 3 months ago that does this. It's got two IR light plane generators in the top corners, and an IR detector array around the bottom and sides. It's multitouch and works great. And this technology DOES make multitouch cheaper. It was $100 less than the other capacitive multitouch displays in the same size.

Doesn't work in the sun, for one thing. For another, it's necessarily going to be pretty bulky; it's not suitable for mobile applications. Since your finger has to interrupt the beam, there will necessarily be a ridge around the outside of your viewing area, which will attract dirt and grime, which will interrupt the IR beams. The resolution is exactly equal to the number of IR senors that you stack around the outside of the thing; it doesn't exactly scale well.

Old stuff is not necessarily bad stuff... I'm at a complete loss as to how this technology could not be viably used to make large multitouch displays more economically viable than the outrageously priced Microsoft Surface.

hogwash in computer years its a billion, its like the Greeks fighting with static electricity on their amber everything, then in 2011 some kids think "well duh we must have been so stupid to not think of a generator based on this concept of statk electricity!"

sounds like a high school 4 person group project in electronics class, oh wait we did a lower resolution version of this back in 1994 as a time killer semester, what "innovations" do we do now?

Why is there so much of this spam popping up on Slashdot lately? Slashdot has historically done well at avoiding comment spam, but it seems that in the past few weeks, I've seen a number of these types of spam.